Research On The Effect Of Sex On Crossed-hands Effect Of Tactile Temporal Order Perception

Temporal order perception is the successive perception of sensory events, which is an important part of temporal perception, including simultaneity, unsimultaneity and sequence. Temporal order perception is influenced by many factors, such as organism variables, stimulus properties, response variables, and so on. Recently, crossed-hands effect is found in the researches of body posture influence on the tactile temporal order perception. In the crossed-hands condition, compared with the uncrossed-hands condition, performance of temporal order judgment decay significantly. Furthermore, the crossed-hands effect would be obtained regardless of the response ways of made by subjects, such as pressing keyboard, responsebox, footpedal, and eye movement.Different theories have been proposed to explain the effect, but neither can fully interpret all the experimental data. It is the key that clarify the influence of the exterior space reference frame and the somatotopic reference frame on crossed-hands effect for researchers. Sex is an important factor influencing the temporal order perception. At present, researches on the factors influencing the crossed-hands effect focus on the exterior space reference frame, the information accessible about the hands posture and the vision experience only. Have no researchers investigate on sex variable. Temporal order judgment task as the typical experimental paradigm is used to investigate whether sex influence on the crossed-hands effect or not. In the three tactile TOJ tasks included in the conditions of crossed-hands and uncrossed-hands, subjects required judgment "on which hand the first stimuli appears" and "on which side the first stimuli appears". Owing to the response ways usually employed in prior studies are difficult to avoid the confuse influence of spacial relation (compatibility or incompatibility) between stimuli and response on the temporal order judgment; Subjects are required make an oral report in this study.Inveatigating whether sex variable affects crossed-hands effect or not in study 1. Uncrossed-hands and crossed-hands posture usually adopted in the studies of crossed-hands effect, and subjects asked to make judgment about "on which hand the first stimuli appears". Temporal order judgment involves somesthesia space and exterior space reference frame, another tactile TOJ task asking subjects to judgment "on which side the first stimuli appears" included in this study to make these two kinds of reference frame have coordinative importance in the tasks. The result shows that significant sex differences occurred just as what we have expected. Performance of male's in all the tasks better than that of female. The result of sex differences in the condition of uncrossed-hands is accordance with the results of prior studies. In crossed-hands conditions, sex have significant influence on the performance when the first stimuli appears on left hand or left space, but sex differences have different result pattern when the first stimuli appears on the right hand or right space.Sex influencing on the crossed-hand effect is explored in longer SOA condition in the study 2. According to the previous results that the temporal order judgment reversal when the SOA is shorter than 300ms, while temporal order accuracy in the crossed-hands tactile TOJ task significantly improved when the SOA longer enough. In such condition, Temporal order accuracy in the crossed-hands tactile TOJ task should has great improved if the marked arm-crossing deficit is rooted in a failure during the process whereby the locations of tactile stimuli are mapped from a somatotopic reference frame onto a more external coordinate system according to the spacial orientation theory. Exploring whether sex variable influences crossed-hands effect in longer SOA condition or not and test the theory explanation in wide time span in this study. The finding reveals that sex differences disappear under longer SOA condition. The current results could not be fully explained by the theories.In this study, the sex influence on the crossed-hands effect in the wide time span is investigated adopted three tactile TOJ tasks in the uncrossed-hands and crossed-hands conditions. we make conclusions as follows:1. Crossed-hands effect is found in the tactile TOJ tasks somatotopic-based and external-based; although subjects required an oral report, verify the existance of crossed-hands effect further.2. Marked sex differences found when the SOA shorter than 150ms maybe have something to do with the ability of space perception, and anatomical diversity between different sexes.3. The theories proposed to explain the crossed-hand effect should be made great improvement. Synthesis modal should be put forward involved personality variables, such as sex, cognitive style, and so on.